Q9550 + EP45-UD3P, need help hitting 4 Ghz please

[mm67]

Ok, I'll get home and try again, but can you please tell me which voltages I should try and tweak to get to 4 GHz?

1. Should I raise Vcore or leave at 1.4?
2. Should I raise CPU Reference to 0.8+?
3. Should I lower VTT a bit?

My Q9550 works best with Cpu ref at 0.76 and MCH ref at 0.80.

[Zach_]

Thanks buddy, I'll make sure to try that, are you also with the EP45-UD3P and what is your clock rate?

[mm67]

Thanks buddy, I'll make sure to try that, are you also with the EP45-UD3P and what is your clock rate?

I have EP45-UD3 which is a budget version of UD3P, same settings usually work on both. I used to run my Q9550 at 4.25 GHz but I recently built an X58 system and gave that P45 for my girlfriend. For her I took the overclock down to 3.8 GHz which that old Q9550 does with stock voltages.

[Zach_]

I'm having a real hard time believing that you reached 3.8 GHz with a Q9550 on stock... Are you certain? That's 1.25 Vcore...

[mm67]

It's actually a bit less than 1.25 V. My Q9550 has stock Vcore of 1.225 V, that with LLC enabled shows 1.20 in Cpu-Z.

[Chike]

Have you found the max CPU frequency you can do with normal vcore(+LLC enabled)?
Maybe you wish to start over from 400x8 and up, with 100MHz increments, and find the lowest voltages possible?

[Zach_]

Those GFlops are not even close to what they should be. How much memory was used?
Try to repeat tests with the same amount of memory, 3072MB if you can, and for 64bit OS LinX is better.
GFlops at 3800 should be 50+.
I can't make what CPU reference is, is it at .760 absolute value? Please list the value for 1.2v e.g.:
MCH Reference [0.8400] ; (0.76 @ 1.2v VTT)
or just
MCH Reference [0.76 @ 1.2v VTT]
The absolute value is not so important.

As I said before there is no point of testing 0.76 @ 1.2v VTT as this is what auto sets.
I migrated the settings I have found stable at high OC to all my OC profiles and it seems they are holding fine, even if not absolutely nesessarry.

I need 1.4v vcore with LLC enabled for 3.8GHz I don't know about your chip, maybe you can get away with less, but we need to try to lower VTT first.

One last thing, set tRD(Static tRead Value in BIOS, Performance Level in MemSet) 10 or 11, for both chabbels for now, later you can try to lower it. Auto sets it too high or disables it altogether.

Well, it seems like I hit a wall, I tried setting the tRD to 11 and CPU skew to 100ps and Windows would not boot properly, kept getting stuck at startup, when it did load it got stuck after 2 minutes of operating. So I removed both settings.

Secondly, I tried pulling 471*8.5 with a Vcore of 1.40-1.425 = Instant BSOD when using IBT, Linx also stopped working twice and the third time threw a BSOD, looks like it won't take anything below 1.4375 and that looks a bit too high.

Chike, should I remain at 3.8 and try to find the ultimate stability for this rate? It looks like the CPU really needs to push it to get to 4 GHz, I guess the chip I got does not overclock that well...

EDIT

About your question, I haven't tried finding the highest clock rate at stock Vcore... how should I go about doing that? Set everything back to Stock and just raise to 400*8 to begin with?

[Chike]

Yes 400x8 with normal vcore(LLC enabled), PLL, and VTT.
MCH Core 1.16-1.24v (try 1.24 first).
I do 3.33GHz with stock vcore, I recon you should be able to have 3.2-3.4GHz at least on stock.

All boardes are different, and luck is also a factor, I have tried yesterday 463x8, and I keep getting memory errors with MCH Core up to 1.32v. Either the CPU or the chipset cannot do it.

[Zach_]

Ok, so I'll go ahead and try that, if I set everything back to stock and run a 5 cycle Linx test for temporary stability, will that be enough? Anything else need testing for temp stability?

P.S. Linx gives me 51 GFlops for 3072MB, more accurate than IBT like you said.

[Chike]

Yes, and try not to change VTT at all while possible to make the system stable at 1.2 by tweaking the references.